PREDICTORS OF OBSTRUCTIVE SLEEP APNEA SYNDROME ACCORDING TO RESULTS OF CLINICAL EXAMINTION AND AMBULATORY BLOOD PRESSURE MONITORING

Objective: to determine the predictors of obstructive sleep apnea syndrome (OSAS) basing on clinical examination, results of night pulse oximetry, daily dynamics of heart rate and blood pressure (BP) in men with newly diagnosed arterial hypertension (AH). Materials and methods. Men (n=197, mean age 40.1 +/- 8.4 years) with newly diagnosed AH of mild (63%), moderate (26%), and severe (11%) degree. OSAS (Apnea-Hypopnea Index [AHI] >= 5 events per hour) was diagnosed in 156 patients (79%). Patients were divided into four groups depending on the AHI. The control group consisted of 31 men without AH and OSAS. Examination included standard clinical, laboratory and instrumental methods, as well as assessment of daytime sleepiness by the Epworth scale. Diagnostics of OSAS and 24-hour BP monitoring were performed on a portable multifunctional recorder. The duration of sleep was determined from the actigraphy data. Statistical analysis was carried out using descriptive statistics, correlation, regression and Receiver Operating Characteristic (ROC) curve analysis. Results. In the studied sample of patients with AH prevailed individuals with central obesity and dyslipidemia. Mean estimate of daytime sleepiness assessed by the Epworth Sleepiness Scale was 7.8 +/- 4.8 points. Of 156 patients with OSAS, its moderate and severe degree (AHI >= 15) was diagnosed in 64%. Predictors of the presence of OSAS were the following: body mass index (odds ratio [OR] 1.13, 95% confidence interval [CI] 1.05-1.22, p<0.002), hypoxemia index (OR 1.12, 95% CI 1.06-1.18, p<0.0001), time indices of hypertension in sleep for diastolic BP (OR 1.03, 95% CI 1.01-1.04, p<0.002) and systolic BP (OR 0.99, 95% CI 0.98-1.00, p<0.045). Basing on these results we created the scoring system for assessment of OSAS risk. The sensitivity of the test was 76%, the specificity - 78%. This model generated a ROC with an area under the curve of 0.848 (95% CI 0.794-0.892, p<0.0001). Conclusion. In men with newly diagnosed AH, snoring and/or daytime sleepiness, predictors of the presence of OSAS were: body mass index, hypoxemia index, and time indices of hypertension during the asleep period for diastolic and systolic BP.